My dad has a 92 f350 4x4 manual trans. He said the truck runs fine from 1st gear through 3rd. Then it starts missing in 4th. No check engine light, he's changed the egr and it didn't fix it. Any ideas on what it might be? He said it idles fine, it just starts to do it when he goes to 4th gear

 

How many miles do the plugs have on them?

 

He said he just changed them

 

Misses under load, cap/rotor plugs wires lately?


Engine?

 

Plugs only?

 

He said he changed all that. Said if your on level ground and hold it at a steady speed it doesn't miss. But if Hanford up the slightest hill or accelerates it more it misses

 

Said it has plenty of power from 1st gear to 3rd, no problems. We're stuck as to what it could be

 

It has the 460 motor

 

Miss under load tends point toward an ignition issue, one that doesn't occur or isn't masked by no load / light load conditions.

Use anything other than Motorcraft plugs?

Good quality parts?

Some of them wonder plugs are just that.....a wonder it started!

If have not checked fuel delivery system, if for no other reason to eliminate it as possible cause of the problem.

 

Thanks for your help. He said he's going to change the distibitor and see if that solves it

 

I have a 94 f150 w/ the 302 and mine was doing the same thing. It was missing under a load usually in overdrive at about 1500-1800 rpm's. I replaced my fuel pressure regulator and it cured the problem. I read a review on the autozone website for the pressure regulator and this individual said it cured his problem too. Good luck.

 

Ok thank you, I'll tell him.

 

not sure if you fixed your problem or not but id be willing to bet your timings off. i had the same problem with my 5.8 and my timing was retarded 7 degrees so i advanced it back to where it needed to be and bam. no miss under load and a ton more power

 

He changed the coil and put a fuel reg. On today and didn't fix it. He's going to try the distr. Next.